Recombinant Human Thyroid Stimulating Hormone for Radioiodine 131I Treatment

This trial is testing whether a hormone medication called recombinant human TSH (rhTSH) — which stimulates thyroid tissue to absorb radioactive iodine — can improve the effectiveness of radioactive iodine (I-131) treatment for patients with thyroid cancer that has returned or spread after surgery. **You may be eligible if...** - You are between 18 and 75 years old - You have differentiated thyroid cancer (the most common type) that came back or spread after a complete or near-complete thyroid removal - Your cancer has been confirmed by imaging, blood markers, or biopsy - You have at least one measurable lesion - Your general health score (ECOG) is 0–2 and you are expected to live more than 3 months - Your blood counts and organ function are within required ranges - Women of childbearing age must use effective contraception and have a negative pregnancy test before starting **You may NOT be eligible if...** - You have uncontrolled high blood pressure, severe heart disease, or uncontrolled diabetes - You are pregnant or breastfeeding - You have active serious infections or other conditions that could interfere with the study Talk to your doctor to see if this trial is right for you.